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From page 651... ... APPENDIX C 651 BOX C-10 Europa Lander Scientific Objectives as Studied Biosignatures: Search for evidence of biosignatures on Europa Identify potential biosignatures through a minimum of 9 lines of evidence: organic abundance, organic patterns, chirality, isotopes, microscale structures, macroscale structures, cellular properties, and biominerals Habitability: Assess the habitability of Europa via in situ techniques Characterize non-ice composition of Europa's near-surface material to determine whether there are environmental factors essential for life Determine the proximity to liquid water and recently erupted materials at the lander's location Surface Properties and Dynamics: Characterize the surface and subsurface of Europa Observe properties of surface materials and connect local proper ties with those seen from remote sensing Characterize dynamic processes of Europa's surface and ice shell over the mission duration Key Features Key Challenges Carrier Stage (7-yr life) Lander science operation within energy and thermal constraints Flight System: Chemical propellant system, 127 m2 solar array, X band communications, radiation vaults to protect avionics, radia- Landing safely on uneven and uncertain terrain tion TID 1.5 Mrad, Bio Barrier for Lander Long-range direct to Earth downlink of science data from lander Deorbit Stage Lander and instrument contamination control for biosignatures science Flight System: Solid rocket motor with 5,000–5,700 kN-s total im pulse, reference design based on Star-48 motor, system includes thermal and separation hardware System mass multipliers with hardware growth Descent Stage: Technical Risk Rating Flight System: Hydrazine monopropellant system with 410 kg Medium: Medium new development, adequate to optimistic margins, propellant, redundant avionics and GNC with Terrain Relative and/or medium risk of achieving major mission objectives as proposed Navigation (TRN) Read the entire page →
From page 652... ... 652 ORIGINS, WORLDS, AND LIFE BOX C-11 Enceladus Orbilander Scientific Objectives as Studied Determine If Enceladus Is Inhabited: Search for biosignatures Characterize amino acids and lipids Search for a polyelectrolyte and any cell-like morphologies Assess to What Extent Enceladus's Ocean Is Able to Sustain Life and Why: Provide geochemical and geophysical context for life detection Quantify physical and chemical environment Determine internal structure, vent structures Find Locations to Land and Actively Sample: Balance science, safety, and planetary protection Find a scientifically compelling landing site with a sufficiently high plume fallout rate Perform reconnaissance for both safe landing and active sampling Find sites with adeqVuate surface temperature to avoid melt Deployed Orbilander through ice crust Key Features Key Challenges Orbilander (10.5-yr life, 7-yr cruise, 1.5-yr orbital mission, 2-yr landed Complexity of TRN + pitch-over landing strategy mission) Payload: Lander/Instrument contamination control for life detection Life Detection: High Resolution Mass Spectrometer (HRMS) Read the entire page →
From page 653... ... APPENDIX C 653 BOX C-12 Enceladus Multiple Flyby Scientific Objectives as Studied Search for Signs of Life in Enceladus Plume Materials: Search for multiple features of life (biosignatures) Multiple, independent measurements of molecular qualities in organic compounds Assess the Habitability of the Enceladus Ocean: Quantitative measurements of key habitability parameters including sources of essential elements and micronutrients, sources of chemical energy, and key physiochemical parameters Characterize Enceladus's Cryovolcanic Activity: Observe details of the structure of Enceladus plume and how it varies in space and time, including a more precise estimation of the relative contributions of jets and curtains to the overall plume Key Features Key Challenges Flyby Vehicle (12-yr life, 9-yr cruise, 3-yr repeat flyby mission) Read the entire page →
From page 654... ... 654 ORIGINS, WORLDS, AND LIFE BOX C-13 Titan Orbiter (Sea Probe Descoped) Scientific Objectives as Studied Geology: Understand the processes actively shaping Titan's surface Geophysics: Understand Titan's interior structure and surface–interior exchange processes Astrobiology/Chemistry: Understand Titan's organic chemistry and path to prebiotic molecules Spacecraft with solar arrays extended Atmosphere: Understand Titan's climate as a source of surface modification Solar arrays eliminated to show the internal configuration of the spacecraft Key Features Key Challenges Orbiter (14-yr life: 10-yr cruise phase, 2-yr Saturn tour phase, 2-yr Titan atmosphere uncertainty impact on flight system for aerosam Titan orbit phase) Read the entire page →
From page 655... ... APPENDIX C 655 BOX C-14 Centaur Orbiter and Lander Scientific Objectives as Studied Understand Early Solar System Compositional Reservoirs: Deter mine isotopic composition, large-scale mineralogical make-up, grain scale composition, and interior volatile composition Understand the Accretion and Dynamical Evolution of Primordial Icy Planetesimals: Determine impact history and relative ages, physi cal characteristics of the body, internal mass distribution, and magne tism present during formation and accretion Determine the Geological and Evolutionary Processes That Have Influenced Icy Planetesimals: Determine landforms and any evidence of changes over the mission; icy regolith characteristics, surface weathering, source and cause of activity (if present) , and characteristics of ring systems Investigate the Biologic Potential of Icy Planetesimals and Poten tial Brine Reservoirs: Determine the thermal history by looking for Deployed Orbiter/Lander alteration minerals; determine the composition, form, and distribution of organic material. Read the entire page →
From page 656... ... 656 ORIGINS, WORLDS, AND LIFE BOX C-15 Uranus Orbiter and Probe Scientific Objectives Origins: When and where did Uranus form in the protosolar nebula? Did Uranus and Neptune migrate or swap positions? Read the entire page →
From page 657... ... APPENDIX C 657 BOX C-16 Calypso: Ariel and KBO Flyby Scientific Objectives as Studied Explore the Uranus System and Its Impact-Generated Moons: (potential ocean worlds) Search for Ariel subsurface ocean and internal structure Characterize Ariel crater populations Uranian System Science: Uranus, rings, ring-moons, and satellites Study Large Kuiper Belt Objects (KBOs) Read the entire page →
From page 658... ... 658 ORIGINS, WORLDS, AND LIFE BOX C-17 Neptune Odyssey, Neptune–Triton Orbiter and Probe Scientific Objectives as Studied Origins: Understand Neptune's origin and how it evolved, placing it in context with other planetary types Particles and Fields: Study Neptune's aurora and magnetic field to understand processes critical to the Neptune system, including explor ing Triton's interactions and whether Triton contains a subsurface ocean by observing auroral activity and magnetic induction Ocean Worlds: Study Triton's surface, interior, atmosphere, and magnetic interaction with Neptune to determine if it is an ocean world, understand plume activity, and how Triton's ionosphere is coupled with Neptune's magnetosphere Comparative Planetology: Compare and contrast attributes of Triton with other Kuiper Belt objects for a better understanding of dwarf planets Satellite and Ring Systems: Understand Neptune's ring-moon system Key Features Key Challenges Orbiter (20-yr life) Availability of SLS Block 2 with Centaur upper stage Payload (14 instruments) Read the entire page →
From page 659... ... APPENDIX C 659 BOX C-18 Triton Ocean World Surveyor Scientific Objectives as Studied Determine whether Triton is an ocean world, ascertain its interior structure, and decide whether Triton's ice shell is in hydrostatic equi Deployed Orbiter PIMS and librium and de-coupled from the interior LORRI out of sight to le Characterize Triton's surface composition and geology, and look for changes, including plumes and their composition Determine the nature of the moon–magnetosphere interaction at Triton Determine the composition, density, temperature, pressure, and spatial/temporal variability of Triton's atmosphere Key Features Key Challenges Orbiter/Lander (20-yr life, 16-yr cruise, 4-yr orbital mission) Lifetime reliability and power issues for long mission duration Payload: (6 instruments) Read the entire page →
From page 660... ... 660 ORIGINS, WORLDS, AND LIFE REFERENCES NASA (National Aeronautics and Space Administration) Read the entire page →
From page 662... ... Appendix D Missions Studied But Not Sent for TRACE As explained in Appendix C, the science mission concepts considered in this report came from three main sources: (1) missions studied by NASA science definition teams (SDTs) Read the entire page →
From page 663... ... APPENDIX D 663 VENERA-D Origin and Rationale This mission concept study was performed by the Venera-D Joint Science Definition Team at the request of the Russian Space Agency, the Institute for Space Research Institute of the Russian Academy of Sciences, and NASA (Venera-D 2019) Read the entire page →
From page 664... ... 664 ORIGINS, WORLDS, AND LIFE Following release from the orbiter, the lander will sample the atmosphere and image the surface during descent to a landing site in a high-latitude region of the northern hemisphere. The lander includes a thermally insulated titanium pressure vessel with thermal storage batteries and is designed to operate for about 3 hours after landing. Read the entire page →
From page 665... ... APPENDIX D 665 Conclusions ADVENTS can address many of the high-priority science objectives for Venus not covered by the VERITAS, DAVINCI, or Envision missions. However, ADVENTS overlaps with some objectives of the VISE mission, resulting in it being given a low priority for a TRACE study. Read the entire page →
From page 666... ... 666 ORIGINS, WORLDS, AND LIFE Mission Challenges A lack of mobility in this mission concept leads to uncertainty in the ability to obtain the needed samples to provide accurate dating of key events, particularly in geologically complex terrains. Top science objectives associated with dating ancient impact basins may be particularly challenging. Read the entire page →
From page 667... ... APPENDIX D 667 Similar to the lunar dating mission (see above) , two different on-board instruments -- one examining rubidium and strontium isotopes and the other potassium and argon isotopes -- are used to determine independent age estimates. Read the entire page →
From page 668... ... 668 ORIGINS, WORLDS, AND LIFE The spacecraft's instrument complement includes the following: full polarization, ultra-high frequency synthetic aperture radar; a dual-band ice-sounding radar; a high-resolution, multiband imager; shortwave and thermal infrared imaging spectrometers, dual stereo cameras, and a wide-angle multispectral imager. Mission Challenges The mission had no novel risks or technical challenges; accommodation of the large radar imager and sounder and their power and data needs drove the SEP implementation choice. Read the entire page →
From page 669... ... APPENDIX D 669 Implementation This large-class mission is designed to conduct simultaneous and systematic observations of the martian climate via eight science investigations carried out by 22 unique science instruments, hosted on 10 individual spacecraft. All are launched on a single Falcon Heavy Recoverable launch vehicle. Read the entire page →
From page 670... ... 670 ORIGINS, WORLDS, AND LIFE Following arrival, 4.1 years is devoted to the selection of sampling sites and sample-collection campaign. The return cruise to Earth takes another 5.7 years. Read the entire page →
From page 671... ... APPENDIX D 671 the spacecraft will encounter a 50–100 km diameter KBO. Once at Pluto, the spacecraft conducts a 3-year tour of the dwarf planet and its five known satellites. Read the entire page →
From page 672... ... Appendix E Panel Missions Not Selected for Additional Study INTRODUCTION As described in Appendix C, each of the survey's six panels reviewed the SDT and PMCS reports and assessed those concepts proposed by the community in white papers and prior proposals. Then the panels identified 18 additional large- and medium-class mission concepts that could address key scientific questions within their respective purviews. Read the entire page →
From page 673... ... APPENDIX E 673 Implementation This concept was proposed as a potential medium-class mission to be implemented by five long-long landers and a supporting orbiter. The landers touch down in a preplanned array within 500 ± 200 km of one another. Read the entire page →

From page 651...

... APPENDIX C 651 BOX C-10 Europa Lander Scientific Objectives as Studied Biosignatures: Search for evidence of biosignatures on Europa Identify potential biosignatures through a minimum of 9 lines of evidence: organic abundance, organic patterns, chirality, isotopes, microscale structures, macroscale structures, cellular properties, and biominerals Habitability: Assess the habitability of Europa via in situ techniques Characterize non-ice composition of Europa's near-surface material to determine whether there are environmental factors essential for life Determine the proximity to liquid water and recently erupted materials at the lander's location Surface Properties and Dynamics: Characterize the surface and subsurface of Europa Observe properties of surface materials and connect local proper ties with those seen from remote sensing Characterize dynamic processes of Europa's surface and ice shell over the mission duration Key Features Key Challenges Carrier Stage (7-yr life) Lander science operation within energy and thermal constraints Flight System: Chemical propellant system, 127 m2 solar array, X band communications, radiation vaults to protect avionics, radia- Landing safely on uneven and uncertain terrain tion TID 1.5 Mrad, Bio Barrier for Lander Long-range direct to Earth downlink of science data from lander Deorbit Stage Lander and instrument contamination control for biosignatures science Flight System: Solid rocket motor with 5,000–5,700 kN-s total im pulse, reference design based on Star-48 motor, system includes thermal and separation hardware System mass multipliers with hardware growth Descent Stage: Technical Risk Rating Flight System: Hydrazine monopropellant system with 410 kg Medium: Medium new development, adequate to optimistic margins, propellant, redundant avionics and GNC with Terrain Relative and/or medium risk of achieving major mission objectives as proposed Navigation (TRN)